Is it good practice to keep your sealed/data classes outside of the class that uses it, or is it better to keep it inside? 1️⃣

class MyViewModel : ViewModel() {
    sealed class SelectedFolder {
        object Unselected : SelectedFolder()
        data class Selected(val id: String) : SelectedFolder()
    }
}

or 2️⃣

private sealed class SelectedFolder {
    object Unselected : SelectedFolder()
    data class Selected(val id: String) : SelectedFolder()
}

class MyViewModel : ViewModel() {

I personally use #2 to make my classes a bit easier to follow

I never used #1, used to use #2, but nowadays I don't even put the children of the sealed class within the sealed class (mainly because it makes referencing the children shorter,

is Selected

instead of

is SelectedFolder.Selected

) On the other hand, i've never wrote a private sealed class 🤔

sealed class SelectedFolder
object Unselected : SelectedFolder()
data class Selected(val id: String) : SelectedFolder()

class MyViewModel : ViewModel() {

we put sealed classes as seperate files just like we would enums. But that's mostly because these sealed classes are used throughout the project or module. unlike @Stephan Schroeder, I prefer nested values for the sealed class. I like treating the sealed class as an enum. The on the fly import assist helps us in immediatly abstracting away the parent selector, just like with enums, but we can still do

SelectedFolder.

and get a list of its children as suggestions.